Question

7
Find the correct order of their boiling points of the following alcohol
methanol. n-propyl alcohol, iso-propyl alcohol
A) methanol <n-propyl alcohol <iso-propyl alcohol
B) methanol >n-propyl alcohol > iso-propyl alcohol
C) methanol < iso-propyl alcohol <n-propyl alcohol
D) methanol > iso-propyl alcohol >n-propyl alcohol​

Answer 1

Explanation:

primary alcohol>secondary alcohol>tertiary alcohol as: pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol.

Answer 2

Option B) methanol >n-propyl alcohol > iso-propyl alcohol

Alcohols' physical characteristics:

• At room temperature, the majority of common alcohols are colorless liquids.
• Alcohols that flow freely and have a fruity scent include methyl, ethyl, and isopropyl.
• The higher alcohols—those with four to ten carbon atoms—are a little greasy or thick and have stronger fruity odors.
• At room temperature, many alcohols with more than 12 carbon atoms and several highly branched alcohols are solids.
• Alcohols have substantially higher boiling points than alkanes with comparable molecular weights.
• For instance, the boiling point of ethanol, which has a molecular weight (MW) of 46, is 78 °C (173 °F), while the boiling point of propane, which has an MW of 44, is 42 °C (44 °F).
• The fact that their boiling temperatures differ so drastically shows that ethanol molecules are attracted to one another considerably more strongly than propane molecules.
• The capacity of ethanol and other alcohols to establish intermolecular hydrogen bonds accounts for the majority of this variation.
• The hydrogen atom's electron density is drawn away from it by the oxygen atom of an alcohol's strongly polarised O-H bond.
• This partially positively charged, polarised hydrogen can form a hydrogen bond with two nonbonding oxygen atom electrons.
• Compared to typical covalent connections, which have binding energies of between 70 and 110 kilocalories per mole, hydrogen bonds, with a strength of about 5 kilocalories (21 kilojoules) per mole, are substantially weaker.

Alcohols are divided into three categories: primary, secondary, and tertiary. The classification is carried out based on whether an alkyl group's carbon atom is joined to a hydroxyl group.

SPJ2